Defending against rockets

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For years, missile defense opponents claimed defenses could not distinguish warheads from decoys and other penetration aids. The solution, they said, was to stop missiles in the first two or three minutes of flight, known as the boost phase, before warheads and decoys are released.

The Missile Defense Agency is trying to meet that challenge with the Airborne Laser (ABL), the nation's primary boost-phase program. But this year, the congressional armed services committees made deep cuts in that program. Those cuts should be reversed.

Eleven years ago, the Air Force let the initial contract to develop an ABL, saying it could "revolutionize aerial warfare in the 21st century." The plan to develop such a weapon grew out of the first Gulf war, when Iraq launched a number of short-range Scuds at U.S. forces and Israel. The Scuds broke up in flight, making it difficult for Patriot PAC-2s to hit them, although many did.

There also was the threat of chemical and biological agents dropped from a missile in small submunitions. It is critical to stop a missile with chemical or biological weapons before they are released, preferably in the boost phase. Similarly, a missile carrying multiple warheads, decoys, balloons or other penetration aids is best stopped before anything is released. The ABL is the best option to do this.

The challenge is to produce an interceptor that is fast enough to strike a missile within a few seconds of launch, when flying slowest and burning brightest. Since nothing is faster than the speed of light, the Air Force turned to lasers on an airborne platform.

The ABL must locate a moving target, generate a powerful beam, send it a long distance, and hold it on target long enough to cause it to rupture. But a laser that can generate that kind of energy is huge. So a major challenge was to reduce the laser's size and weight enough to fit in a 747 aircraft. That goal has been accomplished.

Another challenge was to develop beam and fire control systems that could find, track and target moving missiles. While the weapon is a high-energy laser, the ABL aircraft carries two other lasers and six infrared sensors to detect and track targets. The beam control system is the most sophisticated optical system ever built. These very complex technologies have been in development and testing for the last decade, and the effort is showing real progress.

The prototype aircraft currently holds a surrogate low-power laser substituting for the high-energy laser for test purposes. On July 9, the ABL used its infrared sensors and beam control to find and track Big Crow, a modified C-135 aircraft. On July 13, another flight test put both tracking and surrogate lasers on target after compensating for atmospheric distortion. Cameras on Big Crow showed all the laser beams hitting their targets, successfully demonstrating the entire engagement sequence.

Additional flight tests are being conducted and later this year the high-energy laser will be installed in the aircraft. A lethal demonstration against a ballistic missile is planned in 2009. The program is just two years away from demonstrating it can hit and destroy a missile in the boost phase. Nearly all the hardware has been built and most of the cost has been paid.

The administration asked for $549 million in the 2008 defense budget to complete work and prepare for the 2009 test. The armed services committees both cut the request deeply, the House by $250 million and the Senate by $200 million. These are unusually large cuts. The main rationale is that the limited funds available for missile defense should go to defenses now deployed.

Fielding missile defenses is a high priority, but Congress must take care not to adversely affect what could be a quantum leap in new technology. Deep cuts of the kind made by the committees would cripple the program, cause the loss of laser experts from the only major laser weapon in development, and seriously disrupt the U.S. primary boost-phase defense effort. By contrast, House appropriators cut the ABL request by just $50 million.

It is important to finish testing this advanced technology to see whether high-energy lasers will be practical weapons in future warfare.

An Airborne Laser patrolling near Iran could defend U.S. bases in the Middle East as well as Israel and other allies. And ABLs over the Sea of Japan and Taiwan Strait could protect U.S. bases in the Western Pacific and our allies in Japan, South Korea and Taiwan.

Congress should follow the lead of the House appropriators and provide the funds needed to complete testing this revolutionary weapon system.

James T. Hackett is a contributing writer to The Washington Times based in Carlsbad, Calif.